Endoscopic suture cinch system

ABSTRACT

A two-part suture cinch includes a collar and a plug. A cinch applicator is also provided, and includes an elongate tubular member, a plunger engaged within the distal end of the tubular member, a flexible shaft extending through the tubular member and plunger, and a proximal handle for moving the shaft longitudinally relative to the tubular member. The plunger includes a distal housing for the collar of the cinch, and the plug is coupled to the distal end of the flexible shaft. The suture is thread through the collar and a portion of the applicator. Operation of the applicator draws the plug into the collar and clamps the suture between the plug and collar. In addition, once the plug is coupled in to the collar, the plunger is displaced proximally to release the two-part cinch form the applicator. A method for applying the cinch is also provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device that can be inserted into abody through a natural orifice with an endoscope or other steerableguide member. The present invention may be used in conjunction with asuturing instrument to secure an applied suture to the tissue of amammal, whether human or not, and whether or not alive.

2. State of the Art

Natural Orifice Translumenal Endoscopic Surgery (NOTES) involves passingsurgical instruments in association with an endoscopic camera through anatural orifice, such as the mouth, vagina, or anus, to a desired organ.By avoiding major incisions through the skin, muscle, and nerves of theabdomen, patients may experience a quicker recovery with less pain andscarring while further reducing the post-operative risk of surgery.

In co-owned US Pub. No. 20090312775A1, an endoscopic suturing devicesuitable for use in a NOTES procedure is described. The device has astructure with a sufficiently small distal profile for delivery througha natural orifice, while providing a needle movable on an arm through alarge opening and closing angle and which produces a large force uponthe needle for piercing tissue to perform a surgical operation such astissue approximation and suturing. A length of suture is permanentlyattached to the needle and forms stitches about tissue engaged at thedistal end of the device as the needle is moved through the tissue andthe distal end of the device is moved relative to the tissue. After oneor more stitches have been formed in the tissue, the needle is releasedfrom the device and the free end of the suture is secured relative tothe tissue. In accord with one manner of securing the free end of thesuture, portions of the suture may be tied together about the tissue. Inaccord with another manner of securing the suture, a cinch element isadvanced over the suture and cinches the tissue between the needle onone side of the tissue and the cinch on the other side of the tissue.The suture is then severed.

In addition to the cinch and cinch-applying instrument described in theabove-referenced publication, other cinch instruments and deployablecinches are known. For example, referring to prior art FIG. 1, alsoknown is a cinch applicator 10 for use in deploying the two parts 12, 14of a cinch onto suture 16 in a NOTES procedure. The applicator 10includes an elongate flexible tubular member 18, a hypotube 20 fixed tothe distal end 22 of the flexible tubular member 18, a flexible shaft 24extending through the tubular member 18 and the hypotube 20, and aproximal handle (not shown) for moving the shaft 24 longitudinallyrelative to the tubular member 18. The hypotube 20 defines a distalhousing 26 and a proximal lateral window 28. A slidable plunger 30provided with a guillotine 32 is provided within the hypotube 20, withthe guillotine 32 fully proximal of the housing 26 and distal of thelateral window 28.

The two-part cinch includes a collar 12 and a plug 14 engageable withinthe collar. The collar 12 has a cylindrical outer shape that is retainedin the distal housing 26 of the hypotube 20 with a simple dimplingmating structure. The collar 12 also includes a proximal inner lip 33,and an outer lip 34 seating at the distal end of the hypotube 20 andhaving a flat distal facing end 35. The plug 14 of the cinch is attachedto the distal end of the flexible shaft 24. The plug 14 has an enlargeddistal flange 36 corresponding in size and shape to the outer lip 34 onthe collar 12. The plug 14 has an elongate tubular body 38 defining athroughbore 40 in which the flexible shaft 24 extends, and a proximalcircumferential exterior groove 42. A distal portion of the shaft 24 hasa bend 44 to facilitate retention within the throughbore 40. The distalend of the shaft 24 has a rounded bead 46 that sits at the flange 36 ofthe plug. The bend 44 and the bead 46 trap the flexible shaft relativeto the plug.

In operation, from outside the patient, the proximal end of the suture16 is thread through the collar 12 and hypotube 20 and out of thelateral window 28. Then the applicator 10 is advanced through anendoscope so that the elements of the cinch are provided adjacent thestitched tissue. When the handle is operated, the shaft 24 is retractedto draw the plug 14 into an interference fit within the collar 12, withthe inner lip 33 of the collar positively engaging the outer groove 42on the plug. The suture 16 is captured between the outer surface of theplug 14 and the inner surface of the collar 12 so that the cinch issecured to the suture. Upon further retraction of the shaft 24, theshaft is pulled such that the bend 44 and bead 46 of the shaft 24 arepulled all the way through the plug 14 until released therefrom, anddrawn back into engagement with the plunger 30. As the shaft 24 is movedfurther proximally relative to the hypotube 20, movement of the shaft 24causes the guillotine 32 to slide past the window 28 and sever theproximal portion of the suture 16 from the portion of the sutureattached to the cinch. Once the suture 16 is severed, a jerking motionis applied to the applicator 10 to release the engagement formed by thedimpling structure between to the cinch 12, 14 and applicator 10.

The applicator and cinch are thereby together capable of effectivelysecuring stitched suture to tissue.

SUMMARY OF THE INVENTION

Notwithstanding the effectiveness of the prior applicators and cinches,several improvements have been made which facilitate endoscopicapplication of a two-part cinch to suture. In accord with the invention,a system including a two-part suture cinch and cinch applicator isprovided. The system has particular use in a NOTES procedure in which anendoscopic stitching instrument has applied one or more stitches ofsuture through tissue. In a mode of such stitching, a needle fixed toone of the suture is advanced through the tissue and carries the suturethrough the tissue. Once the tissue is sufficiently stitched toapproximate the tissue, the system of the cinch and cinch applicator isprovided for cinching the suture against the tissue and/or relative tothe suture needle.

The cinch applicator includes an elongate tubular member, a plungerengaged within the distal end of the tubular member, a flexible shaftextending through the tubular member and plunger, and a proximal handlefor moving the shaft longitudinally relative to the tubular member. Thetubular member may be a unitary elongate construct or may be comprisedof a proximal, longer, flexible, first tubular member and a distal,shorter, rigid, second tubular member, such as a hypotube,longitudinally coupled to the distal end of the first tubular member.

The tubular member includes a side window and a latch. The plungerincludes an upper housing, a structure that engages the collar, aguillotine, a floor below the guillotine, and a base provided with acatch engaged by the latch of the tubular member to retain the positionof the plunger within the tubular member. The suture cinch includes acollar and a plug. The collar is provided in the upper housing of theplunger and locked therein by an engagement at the plunger window. Thedistal end of the shaft extends beyond the distal end of the tubularmember in an initial position with the plug coupled to the distal end ofthe flexible shaft. In operation the collar can be extended over thesuture, and the flexible shaft can be withdrawn relative to the tubularmember, drawing the plug into a coupled relationship with the collar andthereby clamping a portion of the suture between the plug and collarwhen the shaft is moved into the applied position. The coupled cinchplug and collar are released from engagement with the applicator and thesuture is severed by movement of the guillotine past the side window ofthe tubular member.

In one embodiment, the cinch collar includes an elongate tubular bodythat is received in the housing of the plunger. The collar body includesa shallow partially circumferential rib that is engaged in a snap-fitengagement with structure of the plunger to lock the longitudinallocation of the collar. When engaged, the collar body extends proximallybeyond the guillotine of the plunger to shield the cutting edge of theguillotine. The collar has a distal outer lip that is received over thedistal end of the tubular member and forms a distal taper that permitsclose approximation to tissue from various angles without damage to thetissue. The proximal end of the collar is stepped to a smaller diameterinner lip.

The cinch plug includes an elongate tubular body substantially longer inlength than the collar. A central portion of the plug body substantiallycorresponds in length to the length of the collar, and has an outerdiameter substantially corresponding to the inner diameter of thecollar. A distal end portion of the plug is bulbous and has a largerdiameter than the central portion. The plug body gradually increases indimension from the central portion to define the bulbous distal endportion, which tapers to a distal tip. A proximal end portion graduallytapers away from the central portion to define a circumferential groovethat corresponds in location with the step at the proximal end of thecinch collar when the collar and plug are mated are discussed below; thegroove is substantially longer than the inner lip. There is no stepwisechange in outer diameter along the central and distal portions of theplug; all diametrical changes are gradual. The proximal end tapers to aproximal tip that is provided with a small barb that can engage theproximal inner lip of the collar. A stepped throughbore is providedwithin the plug with the larger diameter of the throughbore locatedwithin the distal end portion. The flexible shaft is straight all theway through the plug body and includes an end with a bead that isretained in the larger diameter portion of the cinch plug throughbore(but too large to readily pass through the smaller diameter portion).

In operation, a free end of a length of suture attached to tissue mustbe loaded through the applicator. Such suture includes one endpermanently fixed to the needle and located on one side of tissue, and afree end. In one embodiment, the free end of the suture extends througha working channel of an endoscope and out of the user-operated end ofthe endoscope. Loading the suture into the applicator requires advancingthe suture through a pathway defined between the plug and the collar,through the collar and plunger, and out the window of the tubular memberto back outside the applicator. The applicator is then advanced over thesuture through the working channel of the endoscope to the tissue sothat the cinch can be approximated with the tissue.

A suture threader may be provided to facilitate feeding the free end ofsuture through the pathway in the applicator. In one embodiment, thesuture threader includes a distal guide, an intermediate resilientsuture catch, a neck and a proximal handle. In an embodiment, a suturecatch is defined by two arms attached at proximal and distal end andhaving central portions thereof biased away from one another. Thethreader is inserted through the pathway, in the opposite direction fromwhich the suture must be inserted. That is, the guide is inserted fromoutside the applicator, through the window in the tubular member,through the collar and out the distal end of the collar. Once properlypositioned, the catch is located distal of the collar and in an openposition; i.e., with the central portion of the arms biased apart to adimension larger than capable of passing through the collar, the neckextends within the portion of the pathway inside the applicator, and thehandle is provided outside the applicator, preferably adjacent thewindow. The threader is dimensioned such that the open catch, neck, andhandle are fixed in position relative to the applicator until forciblywithdrawn by the user. The applicator is preferably provided with thesuture threader extending through the pathway in its as-assembledconfiguration by a manufacturer.

The suture is then inserted into the catch of suture threader, with alength of the suture drawn through the opening between the arms. Thenthe handle of the threader is pulled proximally to withdraw the threaderfrom the pathway through the applicator, thus forcibly retracting theopen arms against the collar and causing the arms to move against theirbias into a closed position. In doing so, the arms also grasp the sutureand draw the suture through the pathway defined by the collar, theplunger, and the window of the tubular member so that the applicator issituated about the suture ready for cinch application.

In another embodiment, the suture threader includes a proximal endextending out of the endoscope, a thin elongate portion extendingalongside the cinch applicator within the working channel of theendoscope, and a distal portion being a U-shaped loop of suture. Aportion of the threader is inserted through the pathway in the cinchapplicator, with the U-shaped loop of suture extending between the cinchcollar and cinch plug. An endoscopic stitching instrument is operated tomove a suture attached to tissue through the U-shaped loop. The proximalend of the suture threader is actuated from outside the endoscope toretract the loop and cause the suture to be pulled through the pathwayto the load the applicator with suture.

Once the applicator is loaded with suture, the distal end of theapplicator is advanced along the suture until contacted at the locationwhere the suture extends from the tissue. While the applicator is heldat that location, tension is manually applied to the suture (fromoutside the proximal end of the endoscope), and the proximal handle isoperated to move the flexible shaft from the initial position toward theapplied position. As the shaft is moved proximally relative to thetubular member, the plug is drawn into the collar, capturing the suturebetween the exterior of the plug and the interior of the collar. Theshape of the plug (relative to the prior art plug) prevents the shaftfrom prematurely detaching from the plug, which would potentially resultin a misfire. In addition, the locked engagement between the collar andplunger prevents premature release of the collar from the applicator. Asthe plug is completely retracted into the collar, the barb at theproximal end portion of the plug engages the internal lip at theproximal end of the collar, thereby locking the plug to the collar withthe suture trapped therebetween. Further retraction of the flexibleshaft causes the bead at the distal end of the shaft to deform thesmaller diameter portion of the throughbore of the plug and pull throughthe plug to be released from the plug. The bead is retracted against thefloor of the plunger. Further force on the flexible shaft in theproximal direction results in (i) the engagement between the latch ofthe tubular member within the catch of the plunger to permit movement ofthe plunger within the tubular member, (ii) movement of the plungerrelative to the tubular member such that the window of the plunger isretracted from over the rib of the collar, thereby unlocking the collar,freeing the cinch, and allowing the cinch to readily deploy from theapplicator without any additional user activation, and (iii) movement ofthe guillotine into contact with the suture to sever the suture so thatthe cinched suture is freed from remaining suture extending through theworking channel. With the suture cinched against the tissue, theapplicator may then be withdrawn from the endoscope.

The placement of the plunger between the cinch collar and tubular memberprovides several advantages. First, a barrier is provided between theexterior surface of the collar and any sharp features of the tubularmember. Second, the engagement features between the plunger and tubularmember (catch and latch) offer precise component alignment. Third, theengagement features between the plunger and cinch collar (window andouter rib) offer precise location of the collar relative to the plunger.Fourth, because the collar extends back to hide the guillotine from thesuture prior to disengagement of the latch and catch, the suture isprotected from premature cutting. Fifth, the engagement features betweenthe plunger and cinch prevent premature release of the collar untilafter the cinch has been applied.

In addition, the tapered and smoothly transitioning plug and taperedcollar are easier to advance through the working channel on anendoscope. In addition, the longer plug length relative to the length ofthe collar provides a greater length over which the suture is captured.This provides enhanced retention strength. Moreover, the forward end ofthe suture will exit the cinch at the junction between the tapereddistal lip of the collar and the transition between the central portionand the distal end portion of the plug. A large length of the cinch isprovided to each side of the exit portion of the suture. As a result,the cinch may function as a T-tag, rotating from a longitudinalorientation (parallel to the longitudinal axis of the tubular member) toa transverse orientation to lie against the tissue thus providing asignificantly larger contact surface area that provides greaterresistance against tissue.

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptiontaken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial section of a distal end of a prior art cinchapplicator and a prior art two-part cinch.

FIG. 2 is a partial section of a cinch applicator loaded with a two-partcinch according to an embodiment of the invention.

FIG. 3 is an enlarged distal end of view of the inch applicator andtwo-part cinch shown in FIG. 2.

FIGS. 4 and 5 are perspective views showing use of a first embodiment ofa suture threader to thread suture through a pathway of the cinchapplicator according to the invention.

FIG. 6 is a longitudinal section view of the cinch applicator in a firstposition as loaded with suture by the first embodiment of a suturethreader.

FIG. 7 is a longitudinal section view of the cinch applicator, as loadedwith suture by the first embodiment of a suture threader, with theapplicator in a second position in which the cinch plug has been drawninto the cinch collar to clamp suture between the plug and collar.

FIG. 8 is a longitudinal section view of the cinch applicator, as loadedwith suture by the first embodiment of a suture threader, with theapplicator in a third position in which the distal end of the shaft hasbeen drawn through the cinch plug and against the floor of the plunger.

FIG. 9 is a longitudinal section view of the cinch applicator, as loadedwith suture by the first embodiment of a suture threader, with theapplicator in a fourth position in which the plunger has been retractedrelative to the rigid, second tubular member of the cinch applicator.

FIG. 10 is a longitudinal section view of the cinch applicator, asloaded with suture by the first embodiment of a suture threader, withthe applicator in a fifth position in which the plunger has beenretracted to sever the suture and release the cinch.

FIG. 11 is a perspective partial section view of tissue with a cinchedsuture on one side of the tissue and a needle on the other side of thetissue.

FIGS. 12 and 13 illustrate use of a second embodiment of a suturethreader in conjunction with an endoscope and endoscope suture stitchingdevice to thread suture through a pathway of the cinch applicatoraccording to the invention.

FIG. 14 is a longitudinal section view of the cinch applicator in afirst position being loaded with suture by the second embodiment of thesuture threader.

FIG. 15 is a longitudinal section view of the cinch applicator, asloaded with suture by the second embodiment of a suture threader, withthe applicator in a second position in which the cinch plug has beendrawn into the cinch collar to clamp suture between the plug and collar.

FIG. 16 is a longitudinal section view of the cinch applicator, asloaded with suture by the second embodiment of a suture threader, withthe applicator in a third position in which the distal end of the shafthas been drawn through the cinch plug and against the floor of theplunger.

FIG. 17 is a longitudinal section view of the cinch applicator, asloaded with suture by the second embodiment of a suture threader, withthe applicator in a fourth position in which the plunger has beenretracted relative to the rigid, second tubular member of the cinchapplicator.

FIG. 18 is a longitudinal section view of the cinch applicator, asloaded with suture by the second embodiment of a suture threader, withthe applicator in a fifth position in which the plunger has beenretracted to sever the suture and release the cinch.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A cinch applicator and two-part cinch are provided. The system hasparticular use in a NOTES procedure in which an endoscopic stitchinginstrument has applied one or more stitches of suture through tissue.However, it is appreciated that the system may have uses in otherprocedures, particularly other endoscopic procedures. The applicator andcinch may have uses in both open and closed surgical procedures, be usedon humans as well as with other mammals, and may be used in procedureson living individuals as well as cadaverous bodies. The terms ‘proximal’and ‘distal’ have their conventional meaning, with ‘proximal’ referringto a location relatively closer to a user-held and user-operated end ofthe cinch applicator, and ‘distal’ referring to a location relativelyfurther from the user-held and user-operated end.

Referring now to FIG. 2, an embodiment of the cinch applicator 100according to the invention includes an elongate, flexible, first tubularmember 102, a shorter, rigid, second tubular member 104 fixed to thedistal end of the flexible tubular member 102, a plunger 106 engagedwithin the second tubular member 104, a flexible shaft 108 extendingthrough the flexible and rigid tubular members 102, 104 and plunger 106,and a proximal handle 110 for moving the flexible shaft 108longitudinally relative to the tubular members 102, 104. The proximalhandle 110 may include a stationary shaft 110 a and movable slide orspool 110 b conventionally used in association with many endoscopicinstruments. Alternatively, the handle 110 may include a lever rotatablerelative to a stationary member, or a movable trigger, or any othersuitable handle assembly for longitudinally displacing the flexibleshaft 108 relative to the first and second tubular members 102, 104. Theflexible tubular member 102 may be made extruded from a polymer or beformed of a helically wound metal or polymer defining a structural coil,preferably provided with a lubricious sheath to facilitate its passagethrough a working channel of an endoscope. The rigid second tubularmember 104 is preferably a section of a hypotube, although otherconstructs may be used, and may be crimped, bonded or otherwise attachedat the distal end of the flexible first tubular member 102. The plunger106 is preferably molded from plastic. The flexible shaft 108 ispreferably a wire, cable, or other metal or polymeric filamentarystructure capable of being subject to the tensile forces necessary tofunction in accord with the invention described below. That is, theshaft preferably is substantially inelastic and will not be deformed inelongation under the applied tensile forces. The flexible tubular member102 and flexible shaft 108 have sufficient flexibility to be passedthrough a curvilinear working channel of an endoscope; even an endoscopethat is retroflexed.

More particularly, the rigid second tubular member 104 preferably has asufficiently short length that permits its passage through thenon-linear working channel of an endoscope. By way of example, thelength of the rigid tubular member 104 is preferably 12 mm. The rigidtubular member 104 includes a side window 112 and a latch 114. The latch114 is preferably a leaf spring defined by a cut through a portion ofthe side wall of the rigid tubular member 104, the leaf spring extendinginto the interior of the tubular member and capable of being movedradially outward.

The plunger 106 includes an upper housing 116, a partiallycircumferential distal side opening 118, a guillotine 120 distallybordering a central opening 122 coinciding with the side window 112 ofthe rigid tubular member 104, a preferably sloped floor 124 proximallybordering the opening 122, and a base 126 provided with a catch 128. Thecatch 128 may comprise a groove, and is engaged by the latch 114 toretain the longitudinal position of the plunger 106 within the secondtubular member 104. The latch 114 and catch 128 are respectivelypositioned to locate the plunger 106 within and relative to the secondtubular member 104 at a specific location (and a reproducible locationacross the manufacture of many cinch applicators).

Turning now to FIG. 3, the suture cinch includes two components—a collar132 and a plug 134. Each of the collar 132 and plug 134 are preferablymolded or machined from a biocompatible polymer. The collar 132 isprovided in the upper housing 116 of the plunger 106 and is lockedtherein by an engagement between the collar and the plunger, describedmore particularly below. The distal end of the shaft 108 extends, in afirst position, beyond the distal end 136 of the second tubular member104, with the plug 134 coupled to the distal end of the flexible shaft108.

More particularly, the cinch collar 132 includes an elongate tubularbody 140 that is received in the housing 116 of the plunger 106. Thecollar body 140 is preferably approximately 4 mm in length. The body 140includes a shallow partially circumferential rib 142 that is engaged ina snap-fit engagement into the side opening 118 of the plunger 106 tolock the collar to the plunger and relative to the second tubularmember. When engaged, the collar body 140 extends proximally to shieldthe sharp edge of the guillotine 120 of the plunger 106 between thecollar 132 and the second tubular member 104. The collar 132 has adistal lip 144 that is received over the distal end of the secondtubular member 104 and forms a distal taper that permits closeapproximation to tissue from various angles without damage to thetissue. The proximal end of the collar 132 is stepped to a smallerdiameter inner lip 148.

The cinch plug 134 includes an elongate tubular body 150 substantiallylonger in length than the collar 132. By way of example, the cinch plug134 is preferably approximately 8 mm in length that, in view of how thecinch collar 132 and plug 134 are assembled as discussed below, is alsothe total cinch length. A central portion 152 of the plug body 150substantially corresponds in length to the length of the collar 132, andhas an outer diameter substantially corresponding to the inner diameterof the collar. A distal end portion 154 of the plug 134 is bulbous andhas a larger diameter than the central portion 152. The body 150gradually increases in dimension from the central portion 152 to definethe bulbous distal end portion 154, which tapers to a distal tip 156. Aproximal end portion 158 gradually tapers away from the central portion152 to define a circumferential groove 160 that corresponds in locationwith the lip 148 at the proximal end of the cinch collar 132 when thecollar and plug are mated are discussed below; the groove 160 issubstantially longer than the step. There is no stepwise change in outerdiameter along the central and distal portions 152, 154 of the plug. Theproximal end portion 158 tapers to a proximal tip 162 which functions asa small barb that can engage the proximal inner lip 148 of the collar132. A stepped throughbore 164 is provided through the plug 134, withthe larger diameter portion 164 a of the throughbore located within thedistal end portion 154. The flexible shaft 108 is straight all the waythrough the plug body 134 and includes an end with a bead 166 that isprovided in the larger diameter portion 164 a of the throughbore 164(but too large to readily pass through a smaller diameter portion 164b).

The cinch applicator may be provided with a suture threader to assist infeeding a free end of a length of suture stitched to tissue into theapplicator. One embodiment of a suture threader 170 for manually feedingthe free end 172 of a length of suture 174 stitched to tissue into theapplicator 100 is shown in FIG. 4. Suture threader is ideally suited forthreading a length of suture extending from the stitch, through aworking channel of an endoscope and outside the patient suture, and theninto the applicator. It is recognized that, according to a preferred usefor the applicator and cinch, the opposite end of 175 the suture 174 isfixed to a needle 188 located on an opposite side of tissue 180 (SeeFIG. 11, discussed in more detail below). In one embodiment, the freeend of the suture extends from the tissue and through the workingchannel to the user-operated end of an endoscope. Loading the free end172 of suture into the cinch applicator 100 requires advancing thesuture through a pathway defined between the collar 132 and plug 134,through the collar 132, and out through the window 112 of the rigidtubular member 104 to back outside the applicator. The applicator 110 isthen advanced over the suture 174 through the working channel to thetissue so that the two-part cinch 130 can be approximated with thetissue.

The suture threader 170 includes a distal guide 176, an intermediateresilient suture catch 178, a neck 180, and a proximal handle 182. Morespecifically, the suture catch 178 is defined by two arms 178 a, 178 battached at proximal and distal ends and having central portions thereofbiased away from one another to form an eye therebetween that has adimension larger than capable of passing through the collar 132. Thearms are collapsed against their bias and forced through the pathwayfrom a direction opposite from which the suture 174 is to be inserted.That is, the guide 176 is inserted from outside the applicator, throughthe window 112 of the second tubular member 102, and through the collar132 and out the distal end of the collar. Once properly positioned, thesuture catch 178 is located distal of the collar 132 and in an openposition. The threader handle 182 is retained outside the applicator,preferably adjacent the window 112. The threader is dimensioned suchthat the handle 182 and open suture catch 178 are fixed in positionrelative to the applicator until forcibly withdrawn by the user. Theapplicator 100 is preferably provided with the suture threader 170 inposition, in the as-manufactured condition as prepared for use by theuser.

The free end 172 of the suture 174 is then thread into the eye definedby the open arms 178 a, 178 b of the installed suture catch 178.Referring to FIG. 5, then the threader handle 182 is pulled proximallyto withdraw the threader 170 from the applicator 100, thus forciblymoving the arms 178 a, 178 b against their bias into a closed position,as retracted against the collar 132. Referring to FIGS. 5 and 6, theclosed arms 178 a, 178 b grasp the free end 172 of suture 174 and drawthe suture through the pathway defined through the collar 132, theplunger 106, and out of the window 112 of the second tubular member 104so that the suture is thread through the applicator 100 for cinchapplication.

Once the suture 174 is thread through the described pathway of the cinchcollar and cinch applicator (FIG. 6), the distal end of the cinchapplicator is advanced over the suture 174. The suture 174 is pulledtaut, and the distal end of the applicator is advanced along the sutureuntil contacted against the location where the suture enters the tissue.While the applicator is held at that location, tension is manuallyapplied to the suture (from outside the proximal end of the endoscope).Referring to FIG. 7, the proximal handle 110 of the applicator (FIG. 2)is then operated to move the flexible shaft 108 from the initial firstposition toward an applied position. As the shaft 108 is movedproximally relative to the second tubular member 104, the plug 134 isdrawn into the collar 132, capturing the suture 174 between the exteriorof the plug and the interior of the collar. The rounded bulbous shape ofthe plug 134 prevents the plug from inadvertently catching on tissue oranother instrument that could cause premature detachment of the flexibleshaft 108 from the plug 134, and potentially result in a misfire.Specifically, testing has shown that the reduced dimension and roundedshape of the distal end portion 154 of the plug (without a steppedexpansion to a large flattened flange) significantly reduce misfiringassociated with contact of the plug against approximated tissue relativeto the prior art cinch. In addition, the locked engagement between thecollar 132 and plunger 106 prevents premature release of the collar fromthe applicator. As the plug 134 is completely refracted into the collar132, the barb 162 at the proximal end portion of the plug is captured bythe internal step 148 at the proximal end of the collar 132, with theinternal step seating in the groove 160, thereby locking the plug 132 tothe collar 134 with the suture 174 trapped therebetween.

Referring to FIG. 8, further retraction of the flexible shaft 108relative to the rigid tubular member 104 causes the bead 166 at thedistal end of the shaft to slightly deform the smaller diameter portion164 b of the throughbore of the plug 134, and pull through the plug tobe freed from the plug. The bead 166 is retracted against the floor 124of the plunger 106.

Turning to FIGS. 9 and 10, further sufficient force on the flexibleshaft 108 in the proximal direction results in (i) disengagement of thecatch 128 of the plunger 106 from the latch 114 of the second tubularmember 104 to permit movement of the plunger within the second tubularmember, (ii) movement of the plunger 106 relative to the second tubularmember 104 such that the window 118 of the plunger is retracted fromover the rib 142 of the collar 132, thereby unlocking the collar 132 andfreeing the engaged two-part cinch from the applicator, and readying thecinch to deploy from the applicator 100 without any additional useractivation, and (iii) movement of the guillotine 120 into an exposedposition into contact with the suture 174 to sever the suture so thatthe cinch is freed from remaining suture extending through the workingchannel. With the suture cinched against the tissue, the applicator 100may then be withdrawn from the endoscope.

The use of the plunger 106 between the cinch collar 132 and secondtubular member 104 provides several advantages. First, a barrier isprovided between the exterior surface of the collar 134 and the sharpmetal features of a metal hypotube (when such a structure is utilizedfor the second tubular member). Second, the engagement features betweenthe second tubular member 104 and plunger 106 (latch 114 and catch 128)offers precise component alignment. Third, the engagement featuresbetween the plunger 106 and cinch collar 132 offer precise location ofthe collar relative to the plunger. This is important, as the collar canbe precisely positioned to extend back to hide the guillotine 120 fromthe suture 174 prior to intentional cutting, thereby protecting thesuture from premature cutting. Fourth, the engagement features betweenthe plunger 106 and cinch collar 132 prevent premature release of thecinch (or just) collar until after the cinch has been intentionallyapplied.

It is appreciated that the taper-transitioning plug 134 and taperedcollar 132 are easier to advance through the working channel on anendoscope; i.e., the shapes of such components specifically overcomeprior art issues with respect to feeding the structure of componentsthrough a working channel. In addition, the longer length of the plug134 relative to the length of the collar 132 provides a greater lengthover which the suture is captured. This provides enhanced retentionstrength. Moreover, referring back to FIG. 10, the forward end of thecinched suture will exit the cinch at the junction between the tapereddistal lip 144 of the collar 132 and the transition between the centralportion 152 and the distal end portion 154 of the plug 134. A largelength of the cinch 130 is provided to each side of the exiting suture.Referring to FIG. 11, as a result, the coupled cinch 130 may function asa T-tag, rotating from a longitudinal orientation (parallel to thelongitudinal axis of the second tubular member) to a transverseorientation to lie against the tissue 186, thus providing asignificantly larger contact surface area that provides greaterresistance against tissue and thereby prevent pull-through. FIG. 11 alsoshow a needle 188 attached to the suture on the side of tissue oppositethe cinch 130.

It is also appreciated that the suture can be thread through the pathwaywhile the applicator is in situ, i.e., with the applicator extendedthrough the working channel of the endoscope and the applicator locatedadjacent the stitch. Turning now to FIG. 12, an endoscopic stitchinginstrument 200 is shown mounted at the distal end of an endoscope 202.The endoscope includes a first working channel 204 through which aneedle catch device 206 extends and a second working channel 208 throughwhich the cinch applicator 100 extends. The stitching instrument 200includes an arm 210 that rotates a releasable needle 212 in an arcthrough captured tissue 214 and into engagement with the needle catchdevice 206 (the needle shown released from the arm and engaged in thecatch device). A first portion 174 a of the suture extends within thefirst working channel 204 along the outside of the catch device 206, anda second portion 174 b of the suture extends between the tissue 214 andthe needle 212. The needle 212 can be selectively engaged to the needlecatch device 206 and released from the arm 210 for repositioning of thearm relative to the needle 212 and tissue 214 to advance a stitch ofsuture 174. Use of the endoscopic stitching instrument 200 is describedin more detail in co-owned US Pub. No. 20090312775A1. Once the desiredstitch is complete, the cinch applicator 100 is advanced through thesecond working channel 208.

The cinch applicator 100 is provided with another embodiment of a suturethreader 270. The suture threader 270 includes a distal loop 278, acentral portion 280 and a proximal end 282. The distal loop 278 has anopening of sufficient size to receive the needle 212 and as well thesecond portion 174 b of the needle suture 174 therethrough (with thefirst portion 174 a residing outside the loop 278). When the cinchapplicator 100 is fully advanced into the working channel 208, the loop278 is naturally positioned to receive the needle 212 within the loop278 as the arm 210 is rotated to advance the needle into the needlecatch device 206. The distal loop 278 is also sufficiently small to beable to be drawn back through the pathway (defined through the collar132, the plunger 106, and the window 112 of the second tubular member104 (see FIG. 14)) in conjunction with the second portion 174 b of theneedle suture 174. The distal end 278 may comprises a structure otherthan a loop, such as J-shaped construct or another suitable shape forreceiving and retaining the second portion 174 b of the needle suture asit is pulled back through the pathway, and may be made from a materialother than suture. The central portion 280 of the threader 270 ispreferably a elongate flexible element, preferably a strand of suture,extending from the loop 278. At least one of the distal and centralportions 278, 280 extends through the pathway defined through the collar132, the plunger 106, and out of the window 112 of the second tubularmember 104, with the central portion 280 extending alongside the fulllength of the applicator 100, while the applicator is inserted withinthe working channel 208 of the endoscope (i.e., in a position with thecinch plug 134 extending out of the distal end of the endoscope 202, andthe cinch collar 132 located even with or distal the distal face 202 aof the endoscope). The proximal end of the suture threader 282 extendsout of the proximal end of the second working channel 208 and isaccessible to a user of the endoscope to permit manual retraction of thesuture threader 270 relative to the cinch collar 132. The proximal end282 may include a further extension of the suture comprising the centralportion 280, or may be in the form of a finger loop (as shown), adedicated handle, or some integration into the handle 110 (FIG. 2) thatoperates movement of the cinch plug 134 relative to the cinch collar132. Once the stitching instrument 200 has been operated to move theneedle 212 through the loop 278 at the distal end of the threader, aconsequence is that the second portion 174 b of the suture has also beenthread through the loop 278 (with the portion 174 a located outside theloop).

Referring to FIGS. 13 and 14, once the second portion 174 b of thesuture is situated within the loop 278, the proximal end 282 of thesuture threader 270 is manipulated to retract the loop 278 and pull acaptured portion of the distal portion 174 a of the suture toward thecollar 132. As the suture portion 174 b is pulled in this manner (notingthat the suture portion 174 b is coupled to both the tissue 214 and theneedle), the retracted suture portion 174 b is doubled-over (at 174 c)and pulled into and through the pathway (132, 106, 112) and out of theside window 112 in this doubled-over configuration. The distal loop 278may be self-closing as it is pulled (like a noose) to assist inretaining a grip on the suture portion 174 b as its is pulled throughthe pathway (and later cut as described hereinafter). The suturethreader is retracted until the suture is drawn through the side window112. At this point, the distal end loop 278 of the suture threaderresides outside the applicator 100 and within the second working channel208.

With the suture portion 174 b thread through the pathway of theapplicator 100, the applicator is operated as described above to securethe cinch onto the suture. Briefly, with reference to FIG. 15, thedistal end of the collar 132 is advanced to the tissue 214, and cinchwire 108 is moved relative to the hypotube 104 to cause the collar 132to draw the plug 134 into the collar 132, thereby capturing thedoubled-over portion 274 c of suture between the plug and collar. It isappreciated that the collar 132 and plug 134 are appropriatelydimensioned and of a material that accommodates the thickness of thedoubled-over suture portion 274 c. Then, referring to FIG. 16, the cinchwire 108 is retracted relative to the plug 134 to release the bead 166at the distal end of the wire from the plug 134 and draw the bead 166against the floor 124 of the plunger 106. Referring to FIG. 17, as theplunger 106 is fully retracted, the cinch 130 is released frommechanical engagement with the applicator 100. In addition, theguillotine 120 of the plunger 106 begins to move across the window 112.Further retraction of the plunger 106, as shown in FIG. 18, causes theguillotine 120 to be drawn across the doubled-over suture 174 c andsever it, leaving a remaining portion 174 d coupled to the loop 278 ofthe suture threader 270. Once the suture is severed, the suture threader270 may be withdrawn from the endoscope working channel. The appliedcinch 130 has the same advantages described above.

There have been described and illustrated herein embodiments of a cinchapplicator and a method of applying a cinch. While particularembodiments of the invention have been described, it is not intendedthat the invention be limited thereto, as it is intended that theinvention be as broad in scope as the art will allow and that thespecification be read likewise. Thus, while particular dimensions havebeen described for portions of the cinch applicator, it will beappreciated that other suitable dimensions for components can be used aswell. In addition, while preferred dimensions are presented for thetwo-part cinch, it is appreciated that the collar and plug may beprovided in different dimensions as well. Also, while preferredmaterials are described, it is appreciated that other materials can beused. It will therefore be appreciated by those skilled in the art thatyet other modifications could be made to the provided invention withoutdeviating from its scope as claimed.

What is claimed is:
 1. A cinch applicator for applying a suture cinch tosuture, comprising: a) an elongate flexible first tubular member havingproximal and distal ends; b) a relatively rigid second tubular memberhaving proximal and distal ends, said proximal end of said secondtubular member fixed to said distal end of said flexible first tubularmember, said second tubular member defining a side window and defining alatch; c) a plunger situated within said second tubular member, saidplunger having an upper housing for receiving at least a portion of thecinch, a guillotine provided with a cutting edge located distallyrelative to said side window of said second tubular member andretractable past said side window of said second tubular member whensaid plunger is moved proximally relative to said second tubular member,a floor proximal to said guillotine, and a catch engaged by said latchto retain a longitudinal position of said plunger within said secondtubular member; d) a flexible shaft having proximal and distal ends; ande) a proximal handle coupled to said proximal ends of said first tubularmember and said flexible shaft to move said distal end of said flexibleshaft relative to said distal end of said second tubular member.
 2. Acinch applicator according to claim 1, wherein each of said firsttubular member and said shaft have sufficient flexibility to extendthrough a working channel of an endoscope flexed through a non-linearpathway.
 3. A cinch applicator according to claim 2, wherein said secondtubular member is a portion of a metal hypotube.
 4. A cinch applicatoraccording to claim 2, wherein said first tubular member comprises awound coil.
 5. A cinch applicator according to claim 1, wherein saidlatch is a leaf spring.
 6. A cinch applicator according to claim 1,wherein said flexible shaft defines a bead at its distal end.
 7. A cinchapplicator according to claim 1, wherein said proximal handle isoperable to cause said distal end of said flexible shaft to be in, afirst position in which said distal end of said flexible shaft is in alongitudinally advanced location relative to said distal end of saidsecond tubular member, a second position in which said distal end ofsaid flexible shaft is retracted relative to said first position, athird position in which said distal end of said flexible shaft iscontacted against said floor of said plunger, and a fourth position inwhich said distal end of said flexible shaft has applied a sufficientproximal force against said plunger to overcome said latch so that saidplunger is retracted to effect movement of said cutting edge at leastpartially past said side window of said second tubular member.
 8. Acinch applicator according to claim 1, further comprising a cinch collarfor attachment to suture, said cinch collar positioned within saidhousing of said plunger, said cinch collar having an externalprotuberance, said plunger defining a partially circumferential window,and said protuberance engaging within said window to lock said collarwithin said plunger.
 9. A cinch applicator according to claim 1, furthercomprising: a cinch collar provided in said housing of said plunger; anda cinch plug attached to said distal end of said flexible shaft, whereinsaid handle is operable to retract said flexible shaft such that saidcinch plug is drawn back into a coupled engagement with said cinchcollar.
 10. A cinch applicator according to claim 9, wherein said cinchcollar has an external protuberance, said plunger defines a partiallycircumferential window, and said protuberance engages within said windowto lock said collar within said plunger.
 11. A cinch applicatoraccording to claim 9, further comprising a length of suture, said sutureextending through said cinch collar and out of said side window.
 12. Acinch applicator according to claim 9, wherein said collar includes aproximal end that shields said cutting edge from said suture.
 13. Acinch applicator according to claim 12, wherein when said plunger isretracted, said cutting edge is exposed to said suture.
 14. A cinchapplicator according to claim 1, further comprising a cinch including acollar and a plug, said collar engaged within said housing of saidplunger, and collar upon longitudinal displacement of said flexibleshaft.
 15. A cinch applicator according to claim 14, further comprisinga suture threader for retracting the suture from external saidapplicator proximally through said collar into said plunger andlaterally out of said side window.
 16. A cinch applicator according toclaim 15, wherein said suture threader is actuatable to move said suturefrom external said applicator proximally through said collar into saidplunger and laterally out of said side window when said cinch applicatoris located within a working channel of an endoscope.
 17. A cinchapplicator according to claim 16, wherein said suture threader comprisesa distal end having a loop and a flexible longitudinal central portion.18. A cinch applicator according to claim 15, wherein said suturethreader includes an elongate distal guide, a suture catch defining aneye, a proximal threader handle, and a neck joining said suture catchand said threader handle, wherein said suture catch extends at leastpartially beyond said distal end of said second tubular member, saidthreader handle is located outside said first and second tubularmembers, and said neck extends within said second tubular member, andsaid suture catch compressible to be withdrawn through said distal endand side window of said second tubular member when a suitable force isapplied to said threader handle.
 19. A cinch applicator according toclaim 18, wherein said suture catch of said suture threader includesfirst and second resilient arms biased apart from one another to definesaid eye therebetween.
 20. A cinch applicator according to claim 18,wherein: said suture threader is of a generally flat construct.
 21. Acinch applicator according to claim 15, wherein: said suture threader isof a generally flat construct.
 22. A cinch applicator for applying asuture cinch to suture, comprising: a) an elongate tubular member havingproximal and distal ends, said distal end including a side window and afirst engagement member; b) a plunger situated within said tubularmember, said plunger having a distal housing, a proximal floor, and asecond engagement member engaged by said first engagement member toretain a longitudinal position of said plunger within said tubularmember; c) a shaft having proximal and distal ends; and d) a proximalhandle for moving said flexible shaft longitudinally relative to saidtubular member from, a first position in which said distal end of saidflexible shaft is located distal of said floor of said plunger, a secondposition in which said distal end of said flexible shaft is moved intocontact against said floor of said plunger, and a third position inwhich said first and second engagement members are disengaged and saidplunger is moved proximally relative to said tubular member.
 23. A cinchapplicator according to claim 22, further comprising: a releasable cinchcollar engaged within said housing of said plunger, wherein in saidthird position said housing is retracted from over said cinch collar torelease said collar from said housing.
 24. A cinch applicator accordingto claim 23, wherein said plunger includes a cutting edge and in saidfirst and second positions said cinch collar extends proximally beyondsaid cutting edge to shield said cutting edge.
 25. A cinch applicatoraccording to claim 24, wherein in said third position said plunger isretracted relative to said cinch collar to expose said cutting edge. 26.A cinch applicator according to claim 24, wherein said plunger isprovided radially between said cinch collar and said tubular member. 27.A cinch applicator according to claim 23, further comprising: a plug foraxially mating with said cinch collar, said plug releasably coupled tosaid distal end of said flexible shaft.
 28. A cinch applicator accordingto claim 22, wherein said plunger includes a cutting edge, and in saidthird position said cutting edge is moved across at least a portion ofsaid side window.
 29. A cinch applicator according to claim 28, whereinin said third position said cutting edge is moved across said entireside window.
 30. A cinch applicator according to claim 22, wherein saidplunger is close fitting within said tubular member.
 31. A cinchapplicator according to claim 22, wherein said tubular member comprisesa proximal, flexible first tubular member and a distal, rigid, secondtubular member.
 32. A cinch applicator according to claim 22, saidtubular member includes at least a first portion that is flexible, andeach of said first portion and said shaft have sufficient flexibility toextend through a working channel of an endoscope flexed through anon-linear pathway.